A conventional teaching box, including a multifunctional panel and used for a robot, has a color liquid crystal display device, and can highlight or transparentize a color corresponding to a necessary mode key (see, e.g., Patent Document 1). FIG. 13 illustrates a schematic electric configuration. A central processing unit 30 (hereinafter, abbreviated as a “CPU”), a read-only memory 31 (hereinafter, abbreviated as a “ROM”), and a read/write memory 32 (hereinafter, abbreviated as a “RAM”) are operated in accordance with programs that are preliminarily set in the ROM 31, and constitute control means. A touch panel interface 33 (hereinafter, abbreviated as a “touch panel I/F”), and a graphic controller 34 are connected to the CPU 30. The graphic controller 34 temporarily stores images to be displayed in the RAM 35, and controls a state of a image display on a color liquid crystal display device 38 provided on a rear side of a touch panel 37 of a multifunctional panel 36. The touch panel 37 includes transparent switches arranged in a matrix over a display screen of the color liquid crystal display device 38. Data on an input position, at which the data is input by touching a fingertip on the touch panel 37, is input to the CPU 30 via the touch panel I/F 33. The CPU 30 transmits operation data in accordance with an input instruction to a robot control board via a communication interface 19 (hereinafter, abbreviated as a “communication I/F”).
With such a configuration, a color of a color indication corresponding to an invalid key on the touch panel 37 is lightened. When it is determined that a key for a mode to be used is pressed, a predetermined color is highlighted. A user can optionally change a coloration of icons.    Patent Document 1: Japanese Patent No. 2716684 (page 3 FIG. 1)